Readed somewhere that Hagane is belonged to Space Noa class battleship.
She's most powerful in term of firepower since she has Tronium Buster cannon equiped. Other are Shirogane, the weakest of three (appear only twice as NPC in SRW : OG, and blown up both time...) but she has extra PT hangar and catapult. The last is my favourite, Kurogane, has giant reverse gear drill that allow it to travel subterranian.(And ram enemy for heavy damage.)

I liked the Hagane the most, as it suited my concept of a battleship. But I think Shirogane was the coolest-looking, despite the fact that all it did was get creamed by Granzon's Black Hole Cluster. XP